One of my greatest delights over recent years has been receiving emails from Malcolm Brabant.

I could guarantee that a message from the BBC's award-winning Athens-based stringer would be an excellent read - informative, funny and often scathing about those with whom he disagreed.

It was also a pleasure to listen to his reports. He is the kind of journalist who brings subjects alive with wit and insight.

So I was surprised when the riots broke out in Greece that I didn't see or hear much, if anything, of Malcolm on TV and radio. And it's also been a long time since I've heard from him anyway.

The reason, I now discover, is because he has been unwell - extremely unwell - after taking a vaccine that was supposed to protect him from yellow fever.

Aside from his journalism, Malcolm works for UNICEF and he had the jab in advance of going to Pakistan on behalf of the organisation in April this year.

Within 24 hours he was admitted to hospital with a fever and suffering from psychotic effects. And, as Cintia Taylor reports, "he was in a limbo between life and death." He has been in and out of hospital ever since.

Taylor writes: "Doctors suspect the Stamaril vaccine he took in April was contaminated. But both its producer, Sanofi Pasteur, and its Greek distributor, Vianex, have told his family there was nothing wrong with that batch of Stamaril."

Though it is now impossible to establish whether the Stamaril vaccine Malcolm took was contaminated, doctors have found no other evidence that could have caused his illness.

Two days ago (14 November), Sanofi Pasteur's UK communications manager Paul Hardiman told Taylor that the company had investigated Malcolm's case. But it could not find any evidence linking his condition to Stamaril.

The company had tracked the batch of Malcolm's vaccine and says it passed the quality checks.